scholarly journals Actuator-Integrated Fault Estimation and Fault Tolerant Control for Electric Power Steering System of Forklift

2021 ◽  
Vol 11 (16) ◽  
pp. 7236
Author(s):  
Xiangxiang Su ◽  
Benxian Xiao

For the problem of actuator-integrated fault estimation (FE) and fault tolerant control (FTC) for the electric power steering (EPS) system of a forklift, firstly, a dynamic model of a forklift EPS system with actuator faults was established; then, an integrated FE and FTC design was proposed. The nonlinear unknown input observer (NUIO) was proposed to estimate the system states and actuator faults, and an adaptive sliding mode FTC system was constructed based on it. The gain of the observer and controller is obtained by H∞ optimization and one-step linear matrix inequality (LMI) formula operation in order to realize the overall optimal design of an FTC system. Finally, the experimental results show that when actuator failure occurs, the proposed integrated FE and FTC were more accurate than the decentralized design to estimate the system states and the actuator faults. The proposed fault-tolerant controller can more effectively restore the power assist performance of the steering power motor in case of failure and effectively ensure the safety and reliability of the forklift EPS system.

ICTE 2015 ◽  
2015 ◽  
Author(s):  
Chen Huang ◽  
Long Chen ◽  
Kaiding Zhang ◽  
Haobin Jiang ◽  
Chaochun Yuan

Author(s):  
Manel Allous ◽  
Kais Mrabet ◽  
Nadia Zanzouri

Electric power steering is an advanced steering system that uses an electric motor to improve steering comfort of the car. As a result, the failures in the electric motor can lead to additional fault modes and cause damage of the electric power steering system performance. Hence, to ensure the stability of this latter, the present paper proposes a new method to reconfigure the fault control. A novelty approach of fast fault estimation based on adaptive observer is also proposed. Moreover, to guarantee optimal and fast control, a fault-tolerant control based on inverse bond graph modeling is designed to construct the behavior of the nominal system. The simulation and the experimental results on a real electric power steering system reveal the importance of the control strategy and show that the proposed approach works as intended.


2019 ◽  
Vol 9 (19) ◽  
pp. 4010 ◽  
Author(s):  
Ngoc Phi Nguyen ◽  
Sung Kyung Hong

Fault-tolerant control is becoming an interesting topic because of its reliability and safety. This paper reports an active fault-tolerant control method for a quadcopter unmanned aerial vehicle (UAV) to handle actuator faults, disturbances, and input constraints. A robust fault diagnosis based on the H ∞ scheme was designed to estimate the magnitude of a time-varying fault in the presence of disturbances with unknown upper bounds. Once the fault estimation was complete, a fault-tolerant control scheme was proposed for the attitude system, using adaptive sliding mode backstepping control to accommodate the actuator faults, despite actuator saturation limitation and disturbances. The Lyapunov theory was applied to prove the robustness and stability of the closed-loop system under faulty operation. Simulation results show the effectiveness of the fault diagnosis scheme and proposed controller for handling actuator faults.


2011 ◽  
Vol 464 ◽  
pp. 86-89 ◽  
Author(s):  
Da Chong Wang ◽  
Chen Long ◽  
Chen Huang

In order to ensure the safe and reliable operation of electric power steering(eps) system,the fault-tolerant control theory is used to design the feedback control for eps system and the control rule for sensor failure in the linear continuous system is described.On the basis of riccati equation,the design method and steps of fault-tolerant controller are given from the view of optimal control.By taking electric power steering of a certain mini car as research object,the simulation calculation is carried out.By applying such fault-tolerant controller for the eps system,the simulation results show that the system has no sensitiveness to the sensor faults,and the method can satisfy the demand of fault-tolerant control.


Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4109
Author(s):  
Xiaodong Chang ◽  
Jinquan Huang ◽  
Feng Lu

This paper investigated the problem of fault estimation and fault-tolerant control (FTC) against sensor faults for aircraft engines. By applying a second order sliding mode observer (SOSMO) to the engine on-board model, estimations of the system states and sensor faults could be obtained simultaneously, and the result of state estimation was unaffected when using the reduced-order sliding mode system. This result gave rise to the idea to use the estimated states instead of physical sensor signal in the engine close-loop feedback control. Unlike those using passive FTC concepts, the tradeoff between control performance and robustness was inherently unnecessary. Meanwhile, compared to active FTC approaches, because any classical state/output feedback method can be directly applied to the proposed scheme without any controller reconfiguration, extra undesired dynamic responses caused by parameter reconfiguring were avoided. In this paper, the proposed FTC scheme was tested on the nonlinear model of a civil aircraft turbofan engine, and numerical simulation results showed satisfactory sensor FTC performance.


In this paper, the problems of fault estimation and fault-tolerant control for Takagi-Sugeno fuzzy system affected by simultaneous actuator faults, sensor faults and external disturbances are investigated. Firstly, an adaptive fuzzy sliding-mode observer is designed to simultaneously estimate system states and both actuator and sensor faults. Then, based on the online estimation information, a static output feedback fault-tolerant controller is designed to compensate for the effect of faults and to stabilize the closed-loop system. Moreover, sufficient conditions for the existence of the proposed observer and controller with an H∞ performance are derived based on Lyapunov stability theory and expressed in terms of linear matrix inequalities. Finally, a nonlinear inverted pendulum with cart system application is given illustrate the validity of the proposed method.


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